To suffer one miscarriage of justice and endure time inside must be an embittering experience. Hassan Khan says it has happened to him twice.

In 1990 the court of appeal quashed his conviction for armed robbery, raising questions about police integrity and contributing to the disbanding of the notorious West Midlands serious crime squad.

The Criminal Cases Review Commission (CCRC) is now investigating Khan's latest conviction for an entirely different armed robbery. He is currently serving a life sentence, set at a minimum of seven and a half years, in Gartree prison in Leicestershire.

The coincidence of suffering a second mistrial for a similar crime might, at first appearance, stretch the credulity of a judicial panel. Khan's contention is that he has been framed by officers in revenge for bringing a successful civil action against the West Midlands force. His solicitor claims that if you have a record, you are more likely to be set up.

The CCRC's inquiry has been prompted by the fact that the Flying Squad detective who handled evidence against him has since been jailed for the theft of cash from Metropolitan police evidence stores and forging a colleague's signature.

Khan, now 55, from Birmingham, first came to public attention nearly 20 years ago, when the court of appeal freed him because his "confession" – supposedly volunteered on a roundabout car journey through the city – was deemed implausible.

Chris Mullin MP – a campaigner on behalf of the Birmingham Six – later told the Commons: "Students of the West Midlands serious crime squad will recall that [an officer] achieved the remarkable feat of noting down, by torchlight, a lengthy confession from Hassan Khan in a police car travelling at high speed. His evidence was disbelieved by the court of appeal." After years in jail Khan was freed and awarded £23,000 in compensation.

More than a decade later he was charged with carrying out another robbery, using an imitation firearm, at the National Westminster Bank in Sparkhill, Birmingham, on 11 September 2002.

Khan was held in Winson Green prison, where he was interviewed by several officers, including DC Lester Oakley from the Tower Bridge Flying Squad in London, about a series of robberies and a burglary in London and the south-east that year.

He was then charged with an additional seven attacks, including bank, post office and video store robberies using imitation firearms in Croydon, Orpington, Peckham and West Wickham in Kent.

His defence from the outset was that he had been set up in revenge for his legal action against the West Midlands police. In a statement he made in March 2003, he explained that personal property, including bloodstained items, had been stolen from his car around the time of the robberies when he was living in Beckenham and Orpington.

The burglary charge was initially dropped due to a failure to serve the correct papers. In January 2004 Khan went on trial and faced a 17-count indictment. After considering the quality of the evidence all but four of the charges were either dismissed by the judge or returned as not guilty verdicts.

The jury could not agree on the four outstanding charges – those relating to the West Wickham and Sparkhill robberies – so a retrial was ordered. Before the hearing started Khan was recharged with the Croydon burglary.

"Shortly before the case started," his solicitor, Nicola Hall, recalled, "we were told that DC Oakley had been suspended. At first they said it had nothing to do with Hassan Khan's cases but it turned out to involve [some of his] key cases."

The retrial eventually went ahead in September 2005. At that stage Oakley had not yet been convicted. Khan faced charges relating to the three incidents during the five-week trial at Birmingham crown court. He was unanimously acquitted of the Sparkhill Nat West robbery but convicted by a 10-1 majority of the Croydon burglary and the West Wickham Lloyds TSB armed robbery.

The evidence against Khan for the West Wickham robbery relied on DNA traces found on a pair of sunglasses said by the prosecution to have been discovered at the scene. Oakley was one of the first officers at the scene.

Khan's lawyers went to the court of appeal in 2007, arguing that the convictions were unsafe because the trial judge refused to delay proceedings pending the outcome of the case against DC Oakley and admitted evidence of Khan's allegedly bad character. The appeal was rejected.

Last year DC Oakley was unanimously convicted of six counts of theft involving the disappearance of approximately £5,000 in cash from police evidence stores. He was jailed for three years. During that trial, according to Khan's lawyers, it emerged that he had lied on police exhibit documentation relating to Khan's cases, forged a colleague's signature, and stolen rent money he was supposed to use for a surveillance operation.

Khan's lawyers argue that the sunglasses – pivotal in the case against him – had been taken from somewhere else; were never photographed at the scene; were kept in store for two weeks before being tested at a time when Oakley was falsifying exhibits; and that the evidence store was in disarray.

They argue the evidence had either been tampered with or contaminated. An internal Met audit at the time found that the Tower Bridge property store was in a poor state, held items without accompanying records, had lost other items, and operated an inaccurate audit trail. Relations between team members at Tower Bridge Flying Squad were said to be rancorous.

Khan denied committing the burglary. His blood found on a bottle at the scene could have come from a pair of gloves stolen from his car two days earlier, he maintains. He had cut his hand earlier, he says, while changing a wheel on the car.

Oakley's misbehaviour means that Khan's case could merely be "the tip of an iceberg", Hall, his solicitor, believes. "[This conviction] stinks to high heaven," she said. It involves "an officer who has a proven record of dishonesty. There's very clearly been a miscarriage of justice. Had the jury known the facts, they would have come to a very different conclusion."

She hopes the CCRC will re-examine the Crown Prosecution Service file on Oakley, study the Metropolitan Police's internal audit of the Tower Bridge evidence store, and look at the full transcript from Oakley's trial.

"The burglary case does not form part of the reference to the CCRC," Hall explained. "He does not accept guilt but accepts that the principal issue is in relation to the robbery. He does have previous convictions. He's by no means squeaky clean.

"You are not likely to be fitted up if you are squeaky clean. If you have never come to the attention of the police, you are not going to be set up. That's far more likely if you have been in trouble. You are regarded as an easy target."

The CCRC said: "[Khan's] application arrived in August and was allocated to case review in mid-January. It is under review."